SHARING SPACES

Families need to establish a comfort zone when everybody is back under one roof

The verbal and emotional jousting of three generations living under one roof is delightful to watch on “Parenthood,” an NBC drama in which Lauren Graham’s character — with two teenagers in tow — moves in with her retired parents.

Theirs is an increasingly common real-world dynamic, with about 49 million Americans now living in multigenerational households, up from 28 million in 1980, according to a Pew Research Center Social & Demographic Trends study.

But the hilarity and tears and spontaneous dance parties of “Parenthood’s” fictional Braverman household don’t always match up with the reality of parents and their grown children trying to peacefully cohabit.

“We’re commingling what went on when we were children and how we interacted when we were parent and child and resurrecting all those memories and tensions and arguments,” says social psychologist Susan Newman, author of “Under One Roof Again: All Grown Up and (Re)learning to Live Together Happily” (Lyons Press). “If there was anything difficult going on as a child — even something as seemingly remote as sibling rivalry — living with your parents can trigger that.”

We’re also, as a nation, still emerging from a period when it became a stigma to blend the generations. From 1940 to 1980, the number of Americans living in multigenerational households declined from 25 percent to 12 percent, according to the previously mentioned Pew Research study. (Multigenerational is defined as two generations if the children are ages 25 and older, or three or more generations.)

But times they are a-changing. Researchers point to the sluggish economy, of course, but also to the rising age of first marriages and a growing population of immigrants, whose cultures are often more willing to share their homes beyond the nuclear family.

The increased closeness doesn’t have to spell drama and angst, experts say. The living arrangements can actually be a wonderful, enriching experience for all involved, whether an aging parent is moving in with the kids or adult children are crashing with their parents for a spell.

Provided you hatch a plan.

Step 1: Check your attitude. “The most important thing is to view them as members of your family and not as guests,” says David Horgan, co-author of “When Your Parent Moves In: Every Adult Child’s Guide to Living With an Aging Parent” (Adams Media). “When a child spills on your carpet, you might get upset, but you deal with it and move on. When a guest spills on your carpet, you sort of fret, ‘I can’t believe that guy did that.’ You have to accept them and give them unconditional love as a member of the family.”

And remember that all parties are making sacrifices in the arrangement.

“When my mother-in-law moved in, all I saw was what was happening to my schedule and my family dynamic,” admits Horgan. “I wasn’t thinking about everything she had to give up to live with us. She used to garden every day, and now she was living with us in this tight little spot.”

Try to view the setup as a positive development, regardless of what’s driving it.

“A positive attitude is principal in all of this,” Newman says.

Step 2: Establish ground rules. “Boundaries are the most important part of having a healthy relationship when you have everyone under one roof,” Horgan says. “If you make things up as you go, when you do have a conflict, you’re going to be dealing with it during an emotional time.”

For starters: When are they most likely to entertain guests? How often will you all be sharing meals? Who handles what chores? What are the financial arrangements?

“Otherwise you wake up Saturday ... with your hair standing up on end and find some stranger in your house whose car is parked behind yours,” Horgan says.

You’ll also want to address how, if at all, the new arrangements will affect grandparenting.

“Grandparents, in a broader scope, are known for indulging their grandchildren. When you’re living together, some of that might need to be cut back,” Newman says.

Boundaries will preserve the peace ahead of time and protect the relationship for the long haul.

“You’re building a lifelong relationship, and you don’t want to allow the nitty-gritty, (such as), ‘You didn’t fill the car up with gas,’ to undermine the overall picture of your future,” Newman says. “That’s why you set up ground rules.”

Step 3: Let go of the past. View the move as a chance to acquaint yourself with loved ones as they are, not as they were the last time you all shared a kitchen.

“For parents who haven’t lived with their adult children for a number of years — whether it’s four or 24 — you want to remember this isn’t the same person who first left your house,” Newman says. “They’ve had time to mature and develop their own minds and their own positions, likes, dislikes, sleeping habits, partying habits. You want to be mindful not to go back into parent/child mode, but to try to marvel at how this little boy or little girl you raised has become a clearly defined grown-up.”